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Manganese (Mn)-based organic–inorganic metal halides (OIMHs) are extensively employed in various optical applications due to their non-toxicity, superior optical properties, and tunable emission advantages. Developing effective strategies to enhance the optical properties of these materials and clarifying their structure–optical property relationships continue to be of significant interest. Here, we report that the zero-dimensional (0D) (C24H20P)2MnBr4 exhibits remarkable pressure emission tuning that shifts from green to red, a phenomenon driven by the enhancement of the crystal field splitting energy and the reduced energy difference of the lowest d–d transition (4T1 → 6A1) motivated by the shortening of Mn–Br bonds. Additionally, the band gap value of (C24H20P)2MnBr4 becomes 3.13 eV, showing an unexpected decrease by 1.09 eV from an initial value of 4.22 eV, when the pressure is released from 31.0 GPa. The incomplete recovery of the distortion in [MnBr4]2− tetrahedra, impeded by the distortion of soft organic macromolecules, is believed to be responsible for band gap narrowing. Combined with computations and subsequent experiments, it is inferred that pressure induced reduction in the Mn–Br bond distance contributes to the distortion of tetrahedral [MnBr4]2− and larger-sized organic cations. Our work not only elucidates the structure–optical property relationships in Mn-based OIMHs, but also opens new avenues for modulating their optical properties and devising innovative strategies for designing novel Mn-based OIMHs. [ABSTRACT FROM AUTHOR]

The discovery of multifunctional Eu2+-activated luminescent materials with tailored structures and optical properties can address the specific demands of various application fields. Herein, polymorphic SrGa2O4:Eu2+ phosphors exhibiting temperature-induced phase transformation from γ- to β-phase were fabricated. The polymorphic SrGa2O4:Eu2+ phosphors show tuned luminescence properties as a result of phase transition, i.e., emit red light at 620 nm and 614 nm for γ- and β-phases, respectively, under 450 nm blue light excitation. The emission spectrum of the phosphors exactly covers the red spectral region, which can minimize the efficacy loss caused by low eye sensitivity at long wavelengths. Thus, these phosphors can serve as a promising red emitter for warm illumination with a high color-rendering index (Ra) of 83 and a low color correlated temperature (CCT) of 3889 K. Additionally, by utilizing the red emission intensity of Eu2+ as an identification signal, we broaden the application of the red phosphor as a fluorescent probe in operando visualization of catalytic processes. This work presents a novel polymorphic red phosphor and demonstrates tailoring the optical properties of the material by temperature-induced phase transformation and hence enabling multifunctional applications. [ABSTRACT FROM AUTHOR]

A low water-solubility but hydrophilic coating of CaF2 is demonstrated to be effective in mitigating the susceptibility of nickel-rich cathodes to moisture and even water. The ability of the cathode to resist water erosion is not inherently linked to either hydrophobicity or hydrophilicity, but lies in robust chemical bonding within the protective layer exhibiting low water solubility. [ABSTRACT FROM AUTHOR]

In recent years, the pursuit of luminescent thermometer probes with low cost and high sensitivity has become a significant research challenge. This work proposes a strategy that employs lanthanide ions and carbon dots with dual-emission with diverse temperature dependencies to achieve high-temperature sensitivity. Specifically, the fabrication of dual-activated temperature probes has been achieved using NaMgF3:Eu3+/carbon dot nanocomposites through a simple coprecipitation process at room temperature. The optical temperature sensor, NaMgF3:Eu3+/carbon dot, was developed using Eu3+ emission as an internal standard and carbon dot as the temperature signal. The sensor exhibits a substantial absolute sensitivity of 8.3 ± 0.2%K–1 and a relative sensitivity of 2.0 ± 0.1%K–1, both at 300 K, making it a promising candidate for physiological thermometry. Within the temperature range of 300–440 K, the NaMgF3:Eu3+/carbon dot probe shows a relative sensitivity of better than 1.0%K–1 with good excellent repeatability as well as a nearly linear relationship between the Commission Internationale de l'Echlairage chromaticity coordinates of the observed fluorescent color change. The feasibility of the proposed strategy has also been verified by modifying lanthanide ions, e.g., Tb3+. It is anticipated that this pilot study will serve as a springboard for research on dual-mode nanothermometers with superior ratiometric and colorimetric performance. [ABSTRACT FROM AUTHOR]

The discovery of phosphors with highly efficient broadband near-infrared emission is urgent for constructing NIR sources for various applications. Herein, we synthesized a series of near-infrared emitting garnet-type (A3B2C3O12) Lu2−xCaAl3.99Cr0.01SiO12:xGd/La and Lu2CaAl3.99−yCr0.01SiO12:ySc/Ga phosphors and systematically investigated the effect of A/B-site substitution on the crystal structure and luminescence properties. Structural and optical analyses revealed that the A/B-site substitution weakened the crystal field strength, further enhancing the broadband emission of the allowed 4T2 → 4A2transition and diminishing the narrow-peak emission of the forbidden 2E → 4A2 transition. As expected, NIR phosphors, exemplified by Lu1.7CaAl3.99Cr0.01SiO12:0.3Gd and Lu2CaAl3.49Cr0.01SiO12:0.5Sc, showed outstanding thermal stabilities at 423 K (150 °C) registering values of 103.02% and 94.91%, with high quantum efficiencies of 80.48% and 85.01%, respectively. In addition, pc-LEDs with broadband NIR output and good optoelectronic properties have been realized, demonstrating the great potential of broadband NIR pc-LEDs for applications. This work not only provides a series of high-efficiency phosphors for NIR pc-LED applications, but also provides a systematic idea and an efficient method to improve the luminescence performance of garnet-type phosphors. [ABSTRACT FROM AUTHOR]

An in situ gel separator based on an electrospun three-layer nanofibrous membrane (PSE11-Gel) is developed for high-performance lithium-organic batteries (LOBs). The highly efficient shuttle effect inhibition of organic cathode molecules or lithiated intermediates has been demonstrated for PSE11-Gel to realize high-capacity stable LOBs. [ABSTRACT FROM AUTHOR]